From a05e54c103b0b8e1dab5d04b411f1d48387c4903 Mon Sep 17 00:00:00 2001 From: Liu Hua Date: Fri, 18 Apr 2014 09:43:32 +0100 Subject: [PATCH] ARM: 8031/2: change fixmap mapping region to support 32 CPUs In 32-bit ARM systems, the fixmap mapping region can support no more than 14 CPUs(total: 896k; one CPU: 64K). And we can configure NR_CPUS up to 32. So there is a mismatch. This patch moves fixmapping region downwards to region 0xffc00000- 0xffe00000. Then the fixmap mapping region can support up to 32 CPUs. Reviewed-by: Nicolas Pitre Signed-off-by: Liu Hua Signed-off-by: Russell King --- Documentation/arm/memory.txt | 2 +- arch/arm/include/asm/fixmap.h | 16 ++-------------- arch/arm/include/asm/highmem.h | 1 + arch/arm/mm/highmem.c | 27 +++++++++++++++++++++------ arch/arm/mm/mmu.c | 4 ++++ 5 files changed, 29 insertions(+), 21 deletions(-) diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt index d74e8a5901fc..256c5e067fb1 100644 --- a/Documentation/arm/memory.txt +++ b/Documentation/arm/memory.txt @@ -41,7 +41,7 @@ fffe8000 fffeffff DTCM mapping area for platforms with fffe0000 fffe7fff ITCM mapping area for platforms with ITCM mounted inside the CPU. -fff00000 fffdffff Fixmap mapping region. Addresses provided +fffc0000 ffdfffff Fixmap mapping region. Addresses provided by fix_to_virt() will be located here. fee00000 feffffff Mapping of PCI I/O space. This is a static diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index be55ebc08ed4..74124b0d0d79 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -1,20 +1,8 @@ #ifndef _ASM_FIXMAP_H #define _ASM_FIXMAP_H -/* - * Nothing too fancy for now. - * - * On ARM we already have well known fixed virtual addresses imposed by - * the architecture such as the vector page which is located at 0xffff0000, - * therefore a second level page table is already allocated covering - * 0xfff00000 upwards. - * - * The cache flushing code in proc-xscale.S uses the virtual area between - * 0xfffe0000 and 0xfffeffff. - */ - -#define FIXADDR_START 0xfff00000UL -#define FIXADDR_TOP 0xfffe0000UL +#define FIXADDR_START 0xffc00000UL +#define FIXADDR_TOP 0xffe00000UL #define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) #define FIX_KMAP_NR_PTES (FIXADDR_SIZE >> PAGE_SHIFT) diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h index 91b99abe7a95..535579511ed0 100644 --- a/arch/arm/include/asm/highmem.h +++ b/arch/arm/include/asm/highmem.h @@ -18,6 +18,7 @@ } while (0) extern pte_t *pkmap_page_table; +extern pte_t *fixmap_page_table; extern void *kmap_high(struct page *page); extern void kunmap_high(struct page *page); diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c index e05e8ad26ba5..45aeaaca9052 100644 --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -18,6 +18,21 @@ #include #include "mm.h" +pte_t *fixmap_page_table; + +static inline void set_fixmap_pte(int idx, pte_t pte) +{ + unsigned long vaddr = __fix_to_virt(idx); + set_pte_ext(fixmap_page_table + idx, pte, 0); + local_flush_tlb_kernel_page(vaddr); +} + +static inline pte_t get_fixmap_pte(unsigned long vaddr) +{ + unsigned long idx = __virt_to_fix(vaddr); + return *(fixmap_page_table + idx); +} + void *kmap(struct page *page) { might_sleep(); @@ -69,14 +84,14 @@ void *kmap_atomic(struct page *page) * With debugging enabled, kunmap_atomic forces that entry to 0. * Make sure it was indeed properly unmapped. */ - BUG_ON(!pte_none(get_top_pte(vaddr))); + BUG_ON(!pte_none(*(fixmap_page_table + idx))); #endif /* * When debugging is off, kunmap_atomic leaves the previous mapping * in place, so the contained TLB flush ensures the TLB is updated * with the new mapping. */ - set_top_pte(vaddr, mk_pte(page, kmap_prot)); + set_fixmap_pte(idx, mk_pte(page, kmap_prot)); return (void *)vaddr; } @@ -95,7 +110,7 @@ void __kunmap_atomic(void *kvaddr) __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); #ifdef CONFIG_DEBUG_HIGHMEM BUG_ON(vaddr != __fix_to_virt(idx)); - set_top_pte(vaddr, __pte(0)); + set_fixmap_pte(idx, __pte(0)); #else (void) idx; /* to kill a warning */ #endif @@ -119,9 +134,9 @@ void *kmap_atomic_pfn(unsigned long pfn) idx = type + KM_TYPE_NR * smp_processor_id(); vaddr = __fix_to_virt(idx); #ifdef CONFIG_DEBUG_HIGHMEM - BUG_ON(!pte_none(get_top_pte(vaddr))); + BUG_ON(!pte_none(*(fixmap_page_table + idx))); #endif - set_top_pte(vaddr, pfn_pte(pfn, kmap_prot)); + set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot)); return (void *)vaddr; } @@ -133,5 +148,5 @@ struct page *kmap_atomic_to_page(const void *ptr) if (vaddr < FIXADDR_START) return virt_to_page(ptr); - return pte_page(get_top_pte(vaddr)); + return pte_page(get_fixmap_pte(vaddr)); } diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index b68c6b22e1c8..09c0a16165dc 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -35,6 +35,7 @@ #include #include #include +#include #include "mm.h" #include "tcm.h" @@ -1359,6 +1360,9 @@ static void __init kmap_init(void) #ifdef CONFIG_HIGHMEM pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE), PKMAP_BASE, _PAGE_KERNEL_TABLE); + + fixmap_page_table = early_pte_alloc(pmd_off_k(FIXADDR_START), + FIXADDR_START, _PAGE_KERNEL_TABLE); #endif } -- 2.20.1